A payment card (e.g., a credit card) may be used to authenticate payment from a payment account. A cryptographic key may be included in a magnetic stripe of the payment card and used at a point of sale to identify whether the card is a legitimate card. The information in the magnetic stripe may be subject to unauthorized capture, thereby compromising both the payment account and the card. A nefarious user that has made that unauthorized capture may be able to withdraw funds from the payment account using the card one or more times before the unauthorized activity is detected.